With Groundwater Drying Up, Regions Are Quenching Their Thirst With Wastewater

Even though water constitutes over 70 percent of the Earth's surface, many regions are running out of viable water sources. How? Most of the Earth's water – an incredible 97 percent – is located in salt water sources, like oceans and seas, leaving 3 percent for the 7 billion of us and counting. Though methods of desalination exist, it is expensive, time-consuming and rather inefficient. While scientists are working on ways to make desalination more cost- and time-efficient, many regions have been left in a lurch.

In fact, many places around the world rely on groundwater for their basic drinking needs. But, in a quarter of the globe, populations are using groundwater at a pace that far outstrips production. Even worse, many locations where groundwater is being rapidly depleted are agricultural hubs, like India and Pakistan's Upper Ganges, Egypt's Nile River Delta, and California's Central Valley.

Many areas rely on the use of aquifers, or reservoirs of water stored underground and often spread across state boundaries, which have been in existence for thousands of years. They provide drinking and irrigation water and support entire ecosystems, like rainforests. The overuse can lead to dried-up streams and a severe ecological impact.

Tom Gleeson, a hydrogeologist at Quebec's McGill University, and his colleagues studied the use of 800 aquifers throughout the world, estimating their usage and the amount of "recharge." They also accounted for the amount of water needed for ecosystems like grasses, trees and streams.

The researchers found that 20 percent of aquifers are being over utilized; for the Upper Ganges alone, the "groundwater footprint" is more than 50 times the size of the aquifer. That is completely unsustainable. Their article was published in the journal, Nature.

Some areas getting creative with solutions – even resorting to the use of wastewater. In regions like California's Fountain Valley; Melbourne, Australia; Haiti; Israel; and Brazil; households and municipalities capture liquid sewage, highway runoff, laundry water, and rainfall to offset water needs.

Obviously, in such areas, thiswater is not used for drinking water, but are used for commercial and residential purposes. In Hong Kong, seawater is used in airport sinks, washing aircrafts, and in toilets of 80 percent of residents' homes, slashing the need for drinking water in half. Orange County inserts treated wastewater into groundwater, cutting their need for drinking water by 20 percent. Windhoek, Namibia has had a similar system since the 1960's.

Stanley Grant, a University of California-Irvine professor in civil and environmental engineering, and his team have examined the innovative tools that people are using to supplement groundwater. They also reported in their article, published in the upcoming issue of Science, that pipeline leaks and poor accounting are responsible for more than half of the lost groundwater in the developing world. The World Bank estimates that, if even 25 percent of the damages were repaired, 90 million additional people would have access to clean drinking water. Still, they say that three-quarters of residential drinking water is used up by the watering of people's lawns; Grant theorizes that in arid climates like Las Vegas, people will inevitably need to switch to "drought-friendly landscapes."

Though water is undeniably important, Adam Perriman and his fellow investigators at the United Kingdom's University of Bristol has found that at least one organism may not need it. They switched the water coating of myoglobin proteins with a synthetic polymer. In tests to determine how well the protein could move, they found no difference between the water-coated proteins and the synthetic ones. Their findings belie the idea that water is the most important substance on earth, and their findings have been published in the Journal of the American Chemical Society.